Web Filters in Libraries are Not Just About Internet Control

There is an important reason why the use of web filters in libraries is increasing. The cost of providing computers with Internet access to patrons is not inconsiderable, yet in order to qualify for discounts under the E-Rate program, libraries must implement a web filter to comply with CIPA regulations. Libraries must use the web filter to block obscene images (pornography), images of child abuse, and any other graphics that could cause minors to come to harm.

However, there is another reason why the use of web filters in libraries is important. This has been clearly demonstrated this week in St. Louis, MO.

Web Filters in Libraries are Not Only About Internet Control

This week, every computer in the St. Louis Public Library System was taken out of action. Visitors were still able to visit the library and use the books, but do little else. All book borrowing stopped since it is not possible to for library staff to log borrowing on the checkout system. Patrons have also been prevented from gaining access to the Internet. Even the email system has been locked and taken out of action.

What kind of computer malfunction causes the entire network of computers to stop working? The answer is ransomware.

Ransomware is malicious software that has been developed with one sole purpose: To encrypt system and data files to prevent access. Once downloaded, ransomware locks files with powerful encryption preventing files from being accessed. The attacker then sends a ransom demand offering the unique keys to decrypt files in exchange for payment.

Typically, attackers demand $500 in an anonymous currency such as Bitcoin to unlock each computer that has been attacked. In the case of the St. Louis Public Library system, the ransom demand was $35,000. All 700 of the library systems’ computers – across 16 locations – were attacked and encrypted.

Some ransomware variants also act as information stealers. Fortunately for the library, its inventory was unaffected and payment card information and other personal information of patrons were not stolen.

The St. Louis Public Library system will not be paying the extortionate ransom demand. It has instead opted for the only alternative in cases of ransomware infections. To wipe its entire system and reinstall files from backups. That is not a quick process. It could take weeks; certainly days.

The ransom payment may be avoided, but removing the infection will still result in considerable costs being incurred. Then there is the impact the attack has had on patrons of the city’s libraries. The library system is primarily used by poor and disadvantaged individuals. According to library spokesperson Jen Hatton, “For many of our patrons, we’re their only access to the internet.” Hatton also said, “This is their only access to a computer. Some of them have a smartphone, but they don’t have a data plan. They come in and use the Wi-Fi.”

It is not clear how the infection occurred, although there are two main ways that ransomware is installed: Malicious spam email messages and by visiting malicious websites. Both of these attack vectors can be blocked if appropriate software is installed.

Web Filters in Libraries are an Important Ransomware Defense

A spam filter can be used to filter out malicious messages. Those messages contain attachments, which if opened, infect computers or download ransomware. User interaction is required. If the messages are quarantined and not delivered to users’ inboxes, infection can be prevented.

In the case of malicious links contained in emails – an alternative to attachments – a click will direct the user to a malicious website where ransomware is downloaded. Even if a link is clicked, access to the website can be blocked with a web filter. Web filters in libraries can also be configured to stop patrons and staff from visiting malicious sites while browsing the Internet. If a website that is known to be malicious is accessed – deliberately or accidentally – the site will not be displayed and infection will be blocked. Web filters in libraries can also block the downloading of files that are commonly used to infect computers – executable or JavaScript files for example.

The use of web filters in libraries is therefore not just about limiting access to inappropriate and harmful website content. Web filters in libraries are an important cybersecurity protection that can help to ensure that, come what may, patrons will still be able to access the Internet and borrow books.